The present invention relates generally to a speaker system for an automotive audio system. More particularly, the invention relates to a multi-speaker system including a plurality of speakers for stereo-sound reproduction in a vehicle cabin.
Various arrangements of automotive audio speakers are available on the market. Such speaker systems reproduce stereo sound by means of a plurality of speakers to create a stereo acoustic image. The speakers are arranged in the vehicle cabin so that acoustic image or images are formed at suitable points of the vehicle cabin to provide high-quality audio sound. Some speaker systems also employ fader controls and balance controls for adjusting the acoustical pressure produced by each speaker or set thereof.
In another approach, one or more sub-speakers are provided to cooperate with main speakers of the speaker systems. Such a speaker system has been disclosed in Published Japanese Patent Application (Tokkai) Showa No. 58-190200, published on Nov. 7, 1983. In the disclosed system, main speakers reproduce the right- and left-channels of audio sound, and the sub-speakers reproduce monaural sound. This disclosed system is designed to provide higher-quality audio sound for the automotive audio system than even a home stereo system.
However, in this conventional speaker system, it is not always possible to form the acoustic image at points in the vehicle cabin coinciding with the passengers' listening positions. This noticeably degrades the audio sound.